A Shock Condensation Mechanism for Loop Prominences
Forbes, T. G. and J. M. Malherbe, A Shock Condensation Mechanism for Loop Prominences, ApJ, 302, L67 (1986) (ADS)
(click on the image for a larger version)
This cartoon appears to mark the point at which the
CHSKP cartoon
was updated to include a fast-mode MHD shock at the termination of
the reconnection outflow.
At the time of writing, more than three
decades later, the reality of such a feature is still debated, but
it has a potential observational manifestation in the celebrated
(but rare) Masuda phenomenon (see, for example, the 1982
Zaitsev cartoon
or the Jakimiec cartoon for
brave efforts at its explanation).
On the other hand, it does not show the overpressure
dimple expected (but also not
observed), introduced later based on numerical simulations.
But why is a termination shock so rarely observed at radio wavelengths?
By analogy with the "slow drift" meter-wave type II burst, the cartoon
clearly predicts a
"no drift" feature at
the loop-top plasma frequency.
Observations of this, though, are even more rare than observations of the
Masuda phenomenon.
Note that a fast-mode shock had been proposed by
Uchida to explain not only
the type II radio burst, but also the associated
"Moreton wave" in the
chromosphere.
This cartoon appears to mark the point at which the CHSKP cartoon was updated to include a fast-mode MHD shock at the termination of the reconnection outflow. At the time of writing, more than three decades later, the reality of such a feature is still debated, but it has a potential observational manifestation in the celebrated (but rare) Masuda phenomenon (see, for example, the 1982 Zaitsev cartoon or the Jakimiec cartoon for brave efforts at its explanation). On the other hand, it does not show the overpressure dimple expected (but also not observed), introduced later based on numerical simulations.
But why is a termination shock so rarely observed at radio wavelengths? By analogy with the "slow drift" meter-wave type II burst, the cartoon clearly predicts a "no drift" feature at the loop-top plasma frequency. Observations of this, though, are even more rare than observations of the Masuda phenomenon.
Note that a fast-mode shock had been proposed by Uchida to explain not only the type II radio burst, but also the associated "Moreton wave" in the chromosphere.